In one type of patient monitoring systems, a fastener is connected to a monitoring housing by a cord or other device having a fixed length so that if the fastener moves beyond that length, the monitoring system housing is activated. The fastener is connected to a patient such as to the clothing of patient by a clip so that, if the patient moves beyond a fixed distance such as by slumping from a wheelchair onto the floor or moving from a bed, the monitoring housing provides an alarm.
In a prior art monitoring system of this type, the end of the cord opposite to the fastener is loosely fitted into the monitoring housing so that when the patient moves away from the monitoring housing a distance greater than the length of the cord, the opposite end is pulled free. When the opposite end is pulled free from the monitoring housing, an alarm is given. Prior art systems of this type are disclosed in U.S. Pat. Nos. 4,577,185, 4,858,622, and 4,583,084. These types, however, can only be mounted in limited places.
In these patents, the fastener is connected to the monitoring housing by either a plug (U.S. Pat. Nos. 4,577,185 and 4,583,084) or a chip (U.S. Pat. No. 4,858,622). In either case, the plug or the chip (collectively "straight input") inserts into a receptive slot of the monitoring housing. That insertion occurs at 180.degree. relative to the slot. Similarly, the straight input is removed when pulled with a force that occurs near or at about 180.degree. relative to the slot. That 180.degree. pulling force is only possible when the patient is relatively in front of the slot. The straight input is not easily removed when the patient is at any other angles, i.e., 145.degree. to 0.0.degree., relative to the slot. To provide a safe environment under all types of circumstances, the straight input should be easily removable at all angles that the patient can be relative to the monitoring device. Unfortunately, those patents do not disclose such a safe environment.
A problem to solve with the present invention is to design an apparatus and method for monitoring the movement of a patient that provides a safe environment for patients under all circumstances and at all angles relative to the apparatus.